This invention relates to a system and method for emplacing a prosthesis and more particularly, to a reduced profile delivery system and method of use for placement of a bifurcated graft having attachment systems within a corporeal lumen.
It is well established that various fluid conducting bodies or corporeal lumens, such as veins and arteries, may deteriorate or suffer trauma so that repair is necessary. For example, various types of aneurysms or other deteriorative diseases may affect the ability of the lumen to conduct fluids and in turn may be life-threatening. In some cases, the damaged lumen is repairable only with the use of a prosthesis such as an artificial vessel or graft.
For repair of vital vessels, such as the aorta, surgical repair is significantly life-threatening. Surgical techniques known in the art involve major surgery in which a graft resembling the natural vessel is spliced into the diseased or obstructed section of the natural vessel. Known procedures include surgically bypassing the damaged or diseased portion of the vessel and inserting an artificial or donor graft attached to the native vessel by an anastomosis.
It is known within the art to provide a prosthesis for intraluminal repair of a vessel, such as an abdominal aorta having an aneurysm. The art has taught to provide a prosthesis positioned in a vessel and then to secure the prosthesis within the vessel with hooks or staples. Improvements since the earliest prosthesis and intraluminal delivery systems have attempted to increase the flexibility of the entire grafting system and reduce the complexity of the implantation procedure.
More recent art has taught the use of bifurcated grafts having attachment systems configured on each end of the graft prior to delivery. These attachment systems required the use of multiple balloon catheters to expand each of the attachment systems individually. Although these recent improvements simplify the procedure and reduce risks to the patient, more improvement is possible.
In recent years, several devices have been developed in an attempt to treat an aortic aneurysm through intraluminal repair. For example, a method and article for performing an aneurysm repair, wherein a prosthetic graft is utilized to replace the damaged segment of the blood vessel have previously been developed. A plurality of radially spaced anchoring pins are located adjacent each end of the graft and provide means for securing the graft to the wall of the vessel. An assembly is provided for moving the graft within the vessel and permanently anchoring the graft to the wall of the vessel.
Additionally, there has been previously described a bifurcated aortic graft constructed for intraluminal insertion having a plurality of struts having angled hooks with barbs at their superior ends. An assembly for inserting the graft and implanting the hooks into the vessel lumen is also disclosed.
Others have disclosed an intraluminal grafting system including a hollow graft having an attachment means located at one end of the graft. The system includes positioning means for moving the graft within the vessel, the positioning means having a capsule positioned at one end for covering the graft attachment means. The disclosed positioning means further includes an inflatable member for securing the attachment means within the lumen.
Moreover, there has been described an aortic graft and apparatus for repairing an aneurysm that includes a tube graft secured within the aorta and an attachment means at each end of the graft. Intraluminal delivery is accomplished using a catheter having a balloon for expanding and securing the attachment means. The graft and attachment means are preferably enclosed by a sheath which covers the entire graft and attachment means.
There have also previously been developed arrangements including an intraluminal grafting system including a tubular graft having attachment means positioned at both ends. The system includes a positioning means for transporting the graft through a vessel lumen and for deploying the graft within the lumen. The positioning means includes an inflatable member, a capsule and means for removing the graft from the capsule. The capsule is disclosed as a rigid cylindrical member covering the entire graft.
A sheath for use in introducing a catheter in the body of a patient has also been previously described. The sheath includes a flexible elongate tube and a backflow adapter having a hemostatic valve secured to the proximal extremity of the tube. The sheath may be used for introducing a deployment catheter into a femoral artery of the patient. The use of a sheath in such a manner has proven to be beneficial in the delivery and deployment of a graft prosthesis, however, several drawbacks must still be addressed. For example the leading edge of the sheath may cause trauma to the vessel during delivery. One attempt to remedy this problem was introduced in the form of a rigid guard member positioned upon the distal portions of the delivery system that may provide a covering and a smooth transitional surface about the leading edge of sheath thereby buffering the traumatic leading edge from causing damage to the vessel during the delivery of the graft prosthesis. However, this attempted solution has been shown to be of limited benefit as the rigid guard member may cause further complications during the deployment process such as snagging a partially deployed graft during the deployment procedure. Therefore, further improvements may be made to enhance the safety and ease of use of such a system.
To provide consistency with the common usage of terms used in the medical surgical arts in the United States, the terms xe2x80x9cproximal, distal, inferior and superiorxe2x80x9d are used with a certain regularity within the present specification. xe2x80x9cProximalxe2x80x9d refers to parts of the system, such as catheters, capsules and wires, which are closest to the user and closest to that portion of the system lying outside or exterior of the patient. xe2x80x9cDistalxe2x80x9d refers to the point farthest from the user and typically most interior of the corporeal lumen. The term xe2x80x9csuperiorxe2x80x9d refers to a location situated upstream of the flow of blood and is used herein in description of the graft and attachment system. xe2x80x9cInferiorxe2x80x9d refers to the point situated downstream of the flow of blood and again is used herein with reference to the graft and attachment system.
A typical procedure used with the described invention uses a xe2x80x9cfemoral approach.xe2x80x9d This term describes an application which begins with an incision in the femoral artery. Similarly, the described invention may be used in an xe2x80x9ciliac approachxe2x80x9d which begins with an incision in the iliac artery. Using the terminology defined in the previous paragraph, the distal tip of the system maybe inserted into the femoral artery and advanced upstream into the iliac artery and the abdominal aorta. Thus, the more distal portions of the system reside upstream of those portions described as more proximal. Furthermore, in the described procedure, the superior portions of the graft will permanently reside in the abdominal aorta, while the inferior portions will reside in the iliac arteries.
The terms xe2x80x9cipsilateralxe2x80x9d and xe2x80x9ccontralateralxe2x80x9d typically refer to opposing portions of a corporeal lumen having symmetric right and left sides. xe2x80x9cIpsilateralxe2x80x9d refers to those portions residing on the same side through which the grafting system enters the corporeal lumen, while xe2x80x9ccontralateralxe2x80x9d refers to the opposite portions. Therefore, this distinction is dependent on whichever side (right or left) the physician decides to insert the grafting system. The portions of the grafting system which reside or operate within the symmetric vessels of the corporeal lumen use the same terminology. For example, the physician may insert the grafting device into the ipsilateral femoral artery, advance the device through the ipsilateral iliac artery and into the abdominal aorta. Then the device can be manipulated downstream into the contralateral iliac artery.
What has been needed and heretofore unavailable is an improved delivery system that will provide for the atraumatic delivery of a graft prosthesis within the patients vasculature, will not cause further complications during the deployment of the graft prosthesis, and will be fairly easy to use and manipulate by an operating physician. The present invention as described herein fulfills these and other needs.
Briefly and in general terms, the present invention is directed towards repairing vasculature. More particularly, the present invention includes a system that is configured to accomplish intraluminal repair of defects such as aneurysms found in blood vessels.
In one aspect, the system of the present invention includes a catheter for intraluminally delivering an endovascular device at a target site within vasculature.
In one embodiment, the catheter includes a jacket guard configured to provide the system with an enhanced atraumatic profile.
In other aspects, the present invention embodies an intraluminal delivery system for securing a prosthesis within the vessels of the corporeal lumen of an animal, such as a human. The preferred embodiment of a placement system is configured for introducing a graft into a corporeal lumen and positioning the graft in the area of the aortic bifurcation. The delivery system embodies a main catheter capable of containing the prosthesis and placement system for intraluminal delivery. A significant improvement of this system is the use of a main catheter having a smaller diameter from the prior art systems. Another significant improvement is the introduction of a pliable jacket guard located slightly proximal to an expandable member on the main catheter for assisting in the smooth delivery and deployment of a graft prosthesis. The jacket guard which may embody various different forms protects the vessel during delivery of the system by providing a buffer against trauma.
In general, the present invention provides an intraluminal grafting system and method which improves upon the prior art systems. One feature that impacts the capability of any intraluminal device or delivery system is the size of the system""s components. Reducing the size of the components, and ultimately the total delivery system, allows accessing smaller arteries without injury to the artery as well as increasing flexibility. The challenges associated with reducing the size of the system have been met by the present invention. The mechanisms of the present invention have been arranged to fit within a smaller circumferential area than what was capable with prior art devices. Furthermore, the procedures associated with the present invention have been modified to reflect the novel arrangement of the mechanisms. This allows the use of a small diameter delivery catheter having diameter significantly smaller than what is taught in the prior art. The present invention comprises a system and method for implanting a prosthesis utilizing such a small diameter delivery catheter. The small diameter delivery catheter is designed for traversing the femoral, iliac and aortic vessels of a human anatomy.
The present invention also provides an intraluminal grafting system having a pliable jacket guard. Along with the reduced size of the present invention, the pliable jacket guard provides improved safety and accessability to smaller arteries. The jacket guard provides for atraumatic navigation during delivery by embodying a relatively soft leading edge. Furthermore, once the system is properly positioned within a target vessel, the jacket guard further assists in the placement and deployment of a graft prosthesis by providing for a smoother transition between terminal ends of the graft prosthesis which must be securely anchored within the target vessel.
The present system has several advantages over prior art systems. For example, the reduced diameter delivery catheter having a pliable jacket guard causes less trauma to the femoral and iliac arteries while inserting and delivering the grafting system. In addition, the small diameter delivery catheter permits the use of the invention in a larger patient population because of the variances in iliac vessel diameters. Similarly, the smaller system having a pliable jacket guard may allow for easier navigation inside the corporeal lumen especially with more difficult anatomy by reducing the likelihood that vessel injury or trauma will result from any sharp leading edges found on delivery catheters or the like.
The simplified delivery and attachment methods provide advantages to physician and patient which are not available with prior art devices. Ease of use eliminates many of the complications involved with other devices. Shorter procedure times allowed by simplified delivery further reduces the trauma to the patient due to interruption of the flow of blood through the aorta and iliac arteries.
The prosthesis delivered by the present system comprises an inverted wye-shaped bifurcated graft having an attachment system at each of its three orifices. The upper attachment system, which is used to anchor the graft into the abdominal aorta, preferably uses a series of sharpened outwardly disposed members to engage the aorta. The upper attachment system may be balloon-expandable, self-expandable or partially both. The two lower attachment systems, which are used to implant the graft into the iliac arteries, preferably employ self-expanding attachment systems which also support the lower extremities of the graft, but may also be balloon expandable or partially both.
In the preferred embodiment, the two lower attachment systems, comprised of self-expanding attachment systems, are restrained in a compressed condition by release wires residing along side the elements of the attachment systems. These release wires are also described herein as xe2x80x9cpull wiresxe2x80x9d which describes the method by which they release the attachment system. Once the graft is positioned correctly in the aorta and iliac arteries the release wires can be removed, allowing the attachment systems to expand. When the attachment systems are expanded the lower extremities of the graft are attached within the iliac arteries. The release wires can then be entirely removed from the patient leaving the graft securely attached within the iliac arteries.
Preferably, the self-expanding attachment systems in the lower extremities of the graft are arranged to extend superiorly near to the septum of the bifurcation and proximally below the orifice of each lower extremity. For example, the proximal end of the attachment systems may extend approximately 20 mm below the proximal end of the lower extremity. The lower extremities are thus fully supported by the attachment systems when deployed which prevents twisting and bunching of the graft. The graft is also securely attached within the iliac arteries throughout the entire length of the attachment systems. This configuration allows for greater patient activity and mobility without dislodging the graft.
The upper, or superior, member of the graft is positioned by advancing the grafting system through the patient""s vascular system. The grafting system includes a metal catheter ring located at a position corresponding to the attachment system of the superior member of the graft. The metal catheter ring protects the sharp wall engaging members of the graft attachment system during delivery. First the grafting system is inserted into the patient""s ipsilateral femoral artery or external iliac artery. The grafting system is then advanced through the arteries until it passes through the ipsilateral iliac artery, past the aortic bifurcation and into the aorta. The system is then advanced through the aorta until it crosses the aneurysm to be treated. A portion of the main delivery catheter having a metal catheter ring is then withdrawn relative to the remainder of the system exposing the graft. The superior member is thereby located within the aorta superior to the aneurysm.
As the main delivery catheter exposes the graft, the contralateral inferior member is exposed, as well as an attached contralateral delivery system. Preferably the contralateral delivery system includes a contralateral delivery catheter, a contralateral guidewire and a contralateral release wire fastened to the contralateral attachment system. The contralateral guidewire may include a knob or hook on its distal end. This knob or hook is configured to allow the contralateral guidewire to be snared by a wire designed for this purpose which is advanced through the contralateral femoral artery and iliac artery. Once the guidewire is snared the contralateral portion of the grafting system may be guided down into the contralateral iliac artery, and correctly positioned therein.
As the main delivery catheter exposes the graft, the proximal end of the ipsilateral inferior member remains attached within an ipsilateral delivery catheter. This ipsilateral delivery catheter is disposed throughout the main catheter and can be independently translated. It is used to pull the ipsilateral inferior member back into the ipsilateral iliac artery, and correctly position it therein.
Preferably, the delivery system includes a balloon catheter assembly capable of expanding the attachment system of the superior member of the graft. Expanding the system in this manner urges the outwardly disposed members, if present, into the wall of the aorta which is one method of securely fastening the system thereto. The balloon catheter assembly further includes a pliable jacket guard located slightly proximal to the expandable member. The jacket guard provides for a traumatic delivery of the system during placement and deployment of the attachment system of the superior member of the graft. Preferably, the balloon catheter has a multilumen catheter shaft. At least one of these lumens allows the inflation of the balloon. Others house the delivery system for the ipsilateral extremity, the release wire for the ipsilateral self-expanding attachment system, and the main guidewire. Preferably, the release wire is also housed within a small diameter cylinder which allows the balloon catheter to be advanced and retracted relative to the release wire.
The main guidewire extends distally beyond the remainder of the system. The main guidewire also extends proximally throughout the system and out of a control device such that its proximal end can be manipulated by the physician. In this manner the main guidewire may be advanced to a desired location and aid in the manipulation of the remainder of the system. Such a guidewire may be of a configuration typical to prior art procedures, or may be specifically designed for use in a reduced diameter delivery system.
The ipsilateral lower extremity of the graft is deployed into the ipsilateral iliac artery by retracting the ipsilateral release wire. The physician has independent control of the ipsilateral release wire which may be pulled proximally with respect to the remainder of the system. By pulling the ipsilateral release wire proximally it is unfastened from the members of the ipsilateral attachment system and the ipsilateral lower extremity. This allows the ipsilateral attachment system to expand toward the wall of the artery. The ipsilateral release wire and cylinder may then be removed from the patient and the system.
Optionally, once the ipsilateral attachment of the ipsilateral lower extremity is expanded, further securing of the attachment system may be accomplished by positioning the expandable member of the balloon catheter over the expanded ipsilateral attachment system and expanding the expandable member to further expand and engage the ipsilateral attachment system into the vessel wall. This optional procedure is assisted by the pliable jacket guard located slightly proximal of the expandable member. During the positioning of the balloon catheter over the ipsilateral attachment system, the balloon catheter is moved proximally within the partially deployed graft device. This proximal movement of the balloon catheter may cause the partially deployed graft to be buckled or snagged thereby resulting in either dislodgement of the partially deployed graft or at the least, trauma to the vessel wall.
Beneficially, the pliable jacket guard of the present invention reduces the likelihood that the balloon catheter may snag on the graft walls by providing a soft smooth transitional edge surface at the proximal end of the jacket guard. Therefore, it will be appreciated that the jacket guard will improve the safety as well as assist in the delivery of the graft system and the deployment of the graft attachment systems both the superior attachment system and the ipsilateral attachment system.
Once the contralateral lower extremity is correctly positioned into the contralateral iliac artery, it may be deployed in much the same way as the ipsilateral lower extremity. The contralateral positioning system has various possible configurations. All of the configurations allow for the contralateral release wire to be pulled proximally with respect to the remainder of the system and unfastened from the contralateral extremity and contralateral attachment system. Once the contralateral release wire is withdrawn and the contralateral attachment system deployed, the remainder of the contralateral system may be removed from the patient and the system.
The remaining components of the system may be withdrawn from the patient at any time the components are free from the others. This leaves the graft in place and secured across the aortic bifurcation. The bifurcated graft safely maintains the blood flow throughout the region. Once the delivery system components are removed from the body, the access to the corporeal lumens may be closed.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example, the principles of the invention.